Related Experiment Video
Updated: Jun 18, 2026

Fetal Mouse Cardiovascular Imaging Using a High-frequency Ultrasound (30/45MHZ) System
Published on: May 5, 2018
Pattern of HB F level rise during normal pregnancies
Maha Ibrahim1, Mohamad Hasan Qari, Wafa Sait
1Hematology Department, College of Medicine, King Adulaziz University Hospital, Jeddah 21589, Saudi Arabia.
Abstract:
Fetal hemoglobin (Hb F) is the normal hemoglobin (Hb) that is present in the fetus and usually almost absent in adults. The objective of this study was to assess the changes in Hb F levels during normal pregnancy. The level of Hb F was determined in serial blood samples from women at different stages of pregnancy using cation exchange high performance liquid chromatography (HPLC) and compared to age and sex-matched controls. A significant increase (p <0.001) was observed in the level of maternal Hb F; the mean Hb F level during pregnancy was 0.71 +/- 0.51%, while in the non pregnant control group it was 0.28 +/- 0.35%. There was no significant difference in Hb F levels in the three trimester groups using the ANOVA test (F = 0.25). Correlation studies between the gestational age and level of Hb F showed no significant increase of Hb F with advancing pregnancy (R = -0.053, p >0.05). The cause of the rise in Hb F is yet to be elucidated.
Related Concept Videos
Ovarian Cycle
Proliferative Phase
Notably, the stratum basale, the basal layer of the endometrium, including the basal parts of the uterine glands, remains unaffected by menstruation. Stem cells in this layer undergo mitosis, regenerating the stratum functionalis and thickening the...
Fetal Circulation
Two umbilical arteries transport blood from the fetus to the placenta. At the placenta, the blood absorbs oxygen and nutrients while simultaneously eliminating waste products. This oxygen-enriched and nutrient-rich blood then returns to the fetus through one...
Hormonal Regulation of the Menstrual Cycle
At puberty, GnRH begins a pulsatile release pattern, which triggers the anterior pituitary gland to secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The frequency and amplitude of GnRH pulses vary across the menstrual cycle, with faster pulses favoring LH release and slower pulses favoring FSH release.
Pathophysiology of Diabetes
Type 1 diabetes is characterized by autoimmune-mediated destruction of pancreatic β cells, with environmental factors potentially triggering this process in genetically susceptible individuals. Despite many not having a family history, certain genes increase susceptibility, suggesting a...
Gonadal and Placental Hormones
In males, testosterone is the primary gonadal androgen. It plays a central role in the maturation of male reproductive organs — the penis and testes. Additionally, testosterone is instrumental in the development of secondary sexual characteristics — a deep voice as well as facial and pubic hair growth — and...
